I can see why you're undecided. His life circumstances aren't good on paper and point towards him perhaps having issues that will be difficult to deal with once you get to know him better. Anyone can become homeless of course, just as anyone can lose their job, but those two things combined with the drug addiction could be worrying.
I've had a bit of experience with this kind of relationship so I'll share what I learned; my first relationship after my marriage collapsed was with a guy who was technically homeless after having split up with his wife, and was living temporarily with family. When I was first with him he had a job and the homelessness seemed a temporary glitch in an otherwise stable life, but after a few months he stopped going to work after "kicking off" (as he put it) during a meeting and I found out he'd been fired from his past couple of jobs because of being violent towards colleagues and members of the public. It soon became clear he was emotionally very unstable (and emotionally brutal towards me) and I left the relationship grateful that he hadn't become too involved with my family and that I'd never relented and allowed him to move in with me (there was a certain amount of subtle pressure on me to let him move in because he had no home).
He too could play music and was clever and interesting. I've never found anyone else I've had the kind of connection I had with him, and leaving him was the saddest things I've had to do. But as I got to know him better I recognised all the signs of a personality disorder (later verified by diagnosis) that made him difficult to be around at times. He attempted suicide in a way that still leaves me with nightmares.
If I hadn't had children, I might have taken more of a chance on him and seen how things worked out, but because I didn't want my children to be affected by his unstable existence, I bailed out. I have had experience of having a partner with addiction (not the same person) and I can't imagine how difficult it would have been if that had been added to the mix.
People can have hard times and overcome adversity, but go carefully. I'd say take things very slowly and observe him for a while - see him in different moods and in different circumstances, because one of those life issues might be down to bad luck, but three of them together feels like a red flag.